1. Field of the Invention
Aspects of the present invention relate to a vehicular travel guidance device, a vehicular travel guidance method, and a computer program that provides information regarding a charging facility for charging an in-vehicle battery.
2. Description of the Related Art
In the related art, many vehicles are mounted with a navigation device that performs travel guidance for the vehicle in order to enable a driver to easily arrive at a desired destination. The navigation device here is a device that is capable of detecting a current position of a host vehicle with use of a GPS receiver and the like, acquiring map data corresponding to the current position through a network, or a recording medium such as a DVD-ROM, a hard disk drive (HDD), or the like, and displaying such data on a liquid crystal monitor. Further, such navigation device provides information on a category and a position of a facility existing in the vicinity of the current position of the host vehicle and provides information on the position of the facility corresponding to the category designated by a user and a route to the facility.
Also, in addition to a gasoline vehicle having an engine as a drive source, there exist electric vehicles using an electric motor that is driven based on electric power supplied from a battery as the drive source, a hybrid vehicle using the electric motor in combination with the engine as the drive source, and the like.
In order to charge the battery mounted in the electric or hybrid vehicle, there are various methods such as charging the battery with regenerative electric power generated by the motor while the vehicle is decelerating or traveling down a slope, charging the battery with use of a generator driven based on the engine, and also charging the battery at a home or a vehicular charging facility. In addition, in the electric vehicle and the hybrid vehicle, a distance that can be traveled using only the electric motor as the drive force is limited even when the battery is fully charged.
Consequently, in the case of electric and hybrid vehicles, it has been beneficial to provide information on the charging facility provided with a charging unit that is capable of charging the battery. For example, Japanese Patent Application; Publication No. JP-A-2009-25128 discloses a technology that, in addition to displaying a map of the vicinity of the vehicle, calculates, for each charging time of the battery such as 10, 20, and 30 minutes, a travelable area from the current position of the vehicle after the charging. This technology also displays the calculated travelable area on the map, and provides information on the facility located in the travelable area.